Method of manufacturing machine keys



June 30,: 192.5

5. C. MERRICK METHOD OF MANUFACTURING MACHINE KEYS Filed April 21, 1924 /5 /j" DD (htouwq Patented June 30, 1925.

UNITED STATES PATENT OFFICE.

SILA-S C. PIER/RICK, OF NEW BRIGHTON, PENNSYLVANIA, ASSIGNOR TO STANDARD HORSE NAIL 00., OF NEW BRIGHTON, PENNSYLVANIA, A CORPORATION OF PENN- SYLV'ANIA.

METHOD OF MANUFACTURING MACHINE KEYS.

Application filed April 21, 1924. Serial No. 708,015.

New Brighton, Beaver County, State of Pennsylvania, have invented certain new and useful Improvements in Methods of Manufacturing Machine Keys, of which the following is a specification.

This invention relates to the manufacture of what is known to the machinery trade as the lVoodrufi key. In my prior Patent No. 1,112,020, dated Sept. 29, 1914, there is disclosed a method of making keys of this kind in which a milling cutter is arranged to cut across a plurality of rectangular bars the width of which equals the width of the keys to be produced and the thickness of which equals the thickness of the keys. This is a rapid and economical way of producing such keys. However, the material used formaking keys in the manner described is relatively expensive. The cost of such material in the market is generally calculated from a certain base price plus an extra price dependent upon the size of the material. The smaller the size of the material the higher is this extra price. I have found that if wider material is used the extra price for size may be materially lower. The present invention therefore aims to provide a process by which keys of the kind described may be produced from bar material the width of which equals the length of the keys to be manufactured. I have found that by employing material of this kind the keys may be made considerably cheaper. Furthermore. I have found that such wider material may be more easily handled, that a much larger number of the bars can be fastened in the machine and that they will be held more securely. This further tends to reduce the cost of the articles.

The accompanying drawings forming part of the specification illustrate the manner of carrying out the present invention. In said drawings:

Fig. 1 is a side view of a gang cutter for cutting the keys.

Fig. 2 is a sect-ion on the line 2-2 of Fig. 1.

Fig. 3 is a side View illustrating one of the bars from which the keys are to be produced.

Fig. 4 is a side view of a bar partially cut.

bFig. 5 illustrates a series of keys cut from a ar.

Figs. 6 and 7 shows slightly different forms of keys which may be produced by the present process.

According to the present improved method of making keys of the kind described, I arrange a series of bars 10 of suitable material in parallel relation, as shown partly in Fig. 2. These bars are of rectangular cross section and are of a width equal to the length of the keys to be produced. The thickness of the bars is equal to the thickness of the keys to be produced. The bars 10 are suitably clamped to the table of a milling machine which is provided with agang of mill ing cutters 11, rigidly secured on the usual shaft 12, and driven in any desired manner. As illustrated particularly in Figs. 1 and 2, the assembled bars 10 are forced through the cutters 11 transversely of the length of the bars. The cutters 11 are of such size and length that they will cut approximately half-way across the width of the bars, as clearly appears from Fig. 4. Each of these cutters is so shaped as to produce a notch in the edge of the bars, and the series of cutters produce a series of notches. The cutting edges of the cutters 11 are so shaped that the resulting notches produced in the bars have a curved side 13 and a straight side 14 which respectively correspond to substantially one-half of the curved side and one-half of the straight side of a key. After the bars have been passed through the machine and partially out as illustrated in Fig. 4, they are subjected to a second cutting operation preferably by being turned over and accurately positioned and fed a second time through the gang of cutters 11 or similar cutters. This second operation will of course cut a second series of notches in the bars opposite the first series, and such second series of notches will also extend substantially half-way across the width of the bars. This second cutting operation results in completely severing the bars into a plurality of keys. The notches produced during such second operation are of the same shape as those made during the first operation, that is, they are each provided with a curved side 13 and a straight side 14, which curved and straight sides serve to form the rest of the curved sides and the rest of the straight sides of the finished keys.

Special forms of keys such as illustrated in Figures 6 and 7 can readily be produced by the present method and without the em ployment of any special cutters, for example, by merely adjusting the heighth of the bars relative to the cutters, keys such as that illustrated in Fig. 6 having a curved side 15 and straight side 16 and straight ends 17 may be produced. By a different adjustment of the bars relative to the cutters, keys such as illustrated in Fig. 7 having a curved side 18 and straight side 19 and one straight end 20 may be formed.

From the foregoing it is therefore apparent that my present method possesses numerous advantages over that disclosed in said prior patent, from the standpoint of mechanical operation in producing the keys, as well as from the standpoint of cost.

Having thus described my invention what I claim as new and desire to secure by U; S. Letters Patent is:

1. The method of making machine keys having a curved edge and a straight edge which consists in taking a rectangular bar having a width and thickness respectively equal to the width and thickness of the keys produced, cutting a series of spaced notches in one edge of said bar extending approximately half-way across the width of the bar, each of said notches having a curved side which forms part of the curved edge of a partially formed key, and also having a straight side which forms part of the straight edge of a partially formed key cutting a second series of similar s Jaced notches in the other edge of the bar directly opposite the first named notches, the said second series of notches also extending approximately half-way across the width of the bar, L.9l .x.seil .,ber.i sewed t anlui' y olkeys, each of saids co'nd series of notches arse having a curved side which forms the rest of the curved edge of a key, and also having a straight side which forms the rest of the straight edge of a key.

2. The herein described method of making machine keys which consists in clamping together a series of flat bars of rectangular cross section each having a thickness equal to the thickness of the keys to be produced and each being of a width equal to the length of the keys to be produced, passing said bars in a direction transversely of their length through a gang of milling cutters each arranged to cut substantially half-way through said bars from one edge thereof, and shaped to simultaneously form part of the curved sides and part of the straight sides of a plurality of partially formed keys, and then passing said partially cut bars through a gang of milling c'utters arranged to cut substantially half-way through said bars from the other edge thereof, said last named cutters also being shaped. to simultaneously form the rest of the curved sides and the rest of the straight sides of said plurality of keys.

In testimony whereof I hereunto afiix my signature.

SILAS C. MERRICK. 

